Ventilator



July 24, 1934.

R. F. NORRIS VENTILATOR Filed Oct. 14. 1931 5 Sheets-Sheet 1 R. F. NORRIS July 24, 1934.

VENTILATOR Filed oct. 14, 1931 5 Sheets-Sheet 2 Tiel/@nier 770%@670 b/Zor 4M. gc LU, *l

vJuly 24, 1934.

R. F. NORRIS VENTILTOR Filed oct. 14. 1931 5 Sheets-Sheet 3 o vis @www R. F. NORRIS July 24, 1934.

VENTILATOR Filed 061'.. 14, 1931 5 Sheets-Sheet 4 July 24, 1934. R, F NQRRIS 1,967,838

VENTILATOR Filed 001'.. 14. 1951 5 Sheets-Sheet 5 Patented July 24, 1934 vEN'rmAron Ralph Forbnsh Norris, Madison, Wis., assignor to C. F. Burgess Laboratories, Inc., Madison, Wis., a corporation of Delaware Application October 14, 1931, Serial No. 568,693 19 Claims. (Cl. 9894) 'Ihis invention relates 'to improvements in structed of steel. 'I'he air current creating means ventilators, more particularly portable ventilaconsists of two air propellers 12, 12, preferably tors of a type for mechanically supplying noiseforwardly curved multiblade fans mounted on less, filtered anddirectional air to rooms, and both ends of the shaft 13 of electric motor 14.

located in the rooms to beventilated or in spaces Such afan has an axial intake and peripheral G0 immediately adjoining the same.A discharge. 'The motor and fans are supported The object of my invention is the provision above a base 15, (Figs. 3 and 9) the motor being of improved apparatus of the character described, mounted thereon by means of soft rubber bumpthe operation of which is practically noiseless, .ers 16 which prevent the motor vibrations from eincient and convenient of renewal of certain being transmitted to the base. The usual electric 65 parts, and whichvremoves dirt particles and ab'- cord connector is used to connect the motor with sorbs most of the sound.from the air and..causes a source. of electric current, preferably through it to be directed, thereby particularly adapting switch 17 mounted on the cabinet. rllhe air is it for use in oiiices, homes, hospitals, hotels, resdischarged by the fans 12 intol peripheral ducts taurants, banks, .manufacturing plants, apart- 18 and 18 which extend upwardly and converge 70 ments, etc. to form single duct 19. The curvature of these It is a further object to provide a very comducts is such that the resistance .to the air ow pact Ventilating apparatus which may be nis a minimum. It is desirable also to face the outstallecl in a limited space. side surfaces of peripheral ducts 18 and 18 with 2g Other objects will become apparent as the desound-absorbing material 20 for purposes to be 75 -scription progresses when read in connection hereinafter discussed. -lI'he sound-absorbing ma-1 With the aCCOmP-Dying drawings in Which Sevterial 20, such as one half inch or more of hair felt, eral embodiments of the invention are shown: is preferably covered with perforated metal 21 as Fie. l is a perspective view of one embodidescribed and claimed in Norris Patent 1,726,500,

ment of the invention; issued August 27, 1929. The discharge duct 19 80 Fig. 2 is a top plan view thereof; also is made of sound-absorbing construction, Fig. 3 is a front elevation; preferably all of the interior and exterior sur- Fig 4 iS a Perspective View 0f Dart 0f the faces being of perforated metal construction with cabinet; c a sound-absorbing backing such as just described. 4 Fig5 iS a perspective View 0f the all' Intake The interior surfaces of .the ducts absorb the 85 duct; f sounds generated by the motor and other noises Fig. 6 is a perspective View of the motor and blower unit;

Fig. '7 is an enlarged perspective view of a filter entering with the air that may not have been previously absorbed. 'Ihe exterior surfaces of duct 19 form a portion of the intake duct surface basket; and absorb sounds from the incoming air. 90-

Fie. 8 is a plan vlew, partly 1n sectwn. 0f a The motor and fan unit on said base 15, rest mOdCatlOn; centrally on the bottom of cabinet 10, a layer of Fig. 9 is an elevation thereof with the front Vibration absorbing or vibration damping mateof the cabinet removed; rial 20,v such as hair felt, being inserted between Fig- 10 is half elevation and half Section 0f base 15 and the bottom of cabinet 10. A horizon- 95. another H lodlcaflon; tal partition 22 near the top of cabinet 1o divides Flg- 11 1S a sectlon on the Ime 11-11 of Flg' 10; it into a relatively shallow upper chamber 23 and Fig. 12 is a similar view with the parts in a different position;

Fig. 13 is an elevation partly in section of a further modification;

Fig. 14 is a side elevation thereof;

Fig. 15 is an enlarged section of a horizontal plane of certain parts; and

Fig. 16 is an elevation of the latter.

The device, -in the preferred commercial embodiment shown in Fig. 1 is in the form of a cabinet 10 which is usually mounted on legs 11, the length of which. may be regulated to give the ydesired height. The cabinet is preferably COD..-

a deep bottom chamber 24. The horizontal partition contains openings 25 and 26 (Fig. 2) adjacent the end walls of cabinet 10 for the insertion of the filter baskets 27 and 28 (Figs. 3 and '7) In the form of the invention shown in Fig. 3 the 'horizontal partition 22 rests on ledges 29 in the interior of cabinet 10. It is also closely adjacent to the top edge of duct 19. An opening 30 in partition 22 registers with duct 19. The upwardly extending and forwardly curved duct or chamber 31 is mounted on said horizontal partition to regiSCr with duct 19 and terminates in an enlargeno ment or flaring chamber which contains both horizontal louvers 32 adjusted by hand, and vertical defiectors 33, adjusted by a handle 34, the adjustment of the louvers permitting the air to be discharged into the roo-m at any desired angle,'

(both vertical and horizontal) within certain limits. Said louvers are streamlined which not only decreases the air resistance but also eliminates the rushing noise which would otherwise occur. The vertical deflectors are also streamlined. This design insures a quiet operation of the device.

The top of the cabinet 10 or upper chamber 23 is closed by cover 35, felt contact being made with the top edge of cabinet 10. An intake duct 36 (Fig. 1) communicates with an opening near the top of the rear wall of the cabinet 10, to provide an intake for .the air. See also Figs. 4 and 5. The rear end of said duct opens through a panel 37 beneath the lower sash of the window, as shown in Fig. 1, or it may communicate with an opening in a wall. A recirculating valve for recirculating the air in a room, in preference to bringing in fresh air from the outside, is provided in said intake duct and is operated by a handle 38 outside said duct, as shown in Fig. 5. It comprises a transverse opening 39 in the bottom of said duct, the moving part 40 of the valve being substantially flat, and covering said opening, when in the horizontal position in which it is shown inthe drawings.` When said handle, the axis of rotation of which is midway between the top and bottom walls of said duct, is turnedA 90 in a clockwise direction, said flat member is swung .to vertical position and hence obstructs said duct, being of a height and width substantially equal to the internal crossA sectional dimensions of said duct. Thus it operates to selectively shut either the normal duct opening or the opening in the bottom of said duct to respectively recirculate the air or admit fresh air from the outside.

The dirt and dust are filtered from the airby the novel filter baskets 27 and 28, which are supported at their tops in openings 25, 26, in horizontal partition 22 and extend downwardly into chamber 24. Each basket (see Fig. 7) is an opentop wedge-shaped device and consists of two parallel V-shaped end walls 41 with outwardly extending nanges 42 at the top to support the struc-z ture, and inwardly extending flanges 42' on the sides, said end walls being spaced apart by means of cross members 43 and 43', as shown. The two lateral converging walls of the basket consist of screens 44 mounted in frames, consisting of side members and cross member 45, which are hinged at 46, 46 at each side of the top of the basket. The free ends of the frames are clipped together by a pivoted clip or fastener 47. A filter sheet 48 the bottom cross piece 43 of the interior supporting structure and overlaps flanges 42 andv ex tends the full length of the sides to form a complete cover for the converging sides of the interior structure. The screen frames 45 press down on these overlapping marginal portions of the filter sheet and holdthe latter securely in place. The filter sheet may be removed readily by removing the basket from its opening, turning it upside down on a table orother support, opening clip 47 and swinging the screen frames about their axes to release the sheet. A new filter sheet is then folded over the bottom cross-bar 43 (temporarily at the top) and hangs down in the form of a wedge, thepivoted screens 44 being thereafter swung upwardly against the supporting structure Lacasse and held in place by said clip 47, after which the basket is inverted and dropped into the opening in which it fits. The filter sheet may be of vary- .ing porosity and may be of such a texture/that it removes pollen from air. It may be omitted if desired.

In the voperation of the construction described above, the air propellers 12, 12, cause a current of air to be drawn in through the duct 36, upper chamber 23, and thence downward through openings 25 and 26 in horizontal partition 22 into the vertical intake flues of lower chamber 24, these flues being formed by the end walls of cabinet 10 and the walls of the fan ducts and discharge ducts as previously described. If the filter baskets 42 are inserted in openings 25 and 26 the air passes through the filter sheets and is cleaned before entering axially into air propellers 12, 12, from. which it is discharged upwardly through discharge duct 19 and then forwardly into the upper directing chamber 31 and out through louver 32. 'Ihe silencing of the ventilator preferably is increased by installing sound-absorbing panels 50 and 51 on the portions of the cabinet walls forming the intake fiues of lowerchamber 24. Sound-absorbing treatment may be used on other walls and surfaces if this is found necessary.

Fig. 8 shows a modification of the upper air directing chamber. ond hood or turret 53, fitting over the opening` 30 in the partition 22. Said turret has a curved Insideof a hood 52 is a ysecpartition 54 therein providing two more or less sible from the outside of the cabinet, and since the front of said turret is open, the air being discharged therefrom may be directed through the horizontal louvers 32 which latter may direct the air upwardly or downwardly. By turning the turret, the air may also be directed in one direction or another, in a more or less horizontal plane so that the air may be caused to` issue from the device at any desired angle, vertically or hori- Zontally, within the limits of the structure. By having the sides of turret 53 curved inwardly at its outlet as shown in Fig. 8, the air is directed into the room in a concentrated stream or pencil and does not spread out fan-wise. The remaining parts of the device are substantially the same as those previously described and the same reference numerals have been applied thereto.

It is often desirable to install permanently, a ventilator of the type described, in a wall 60, as in the space below a window frame. When this is done the cover of the cabinet cannot be removed, and it is impossible to remove the filter baskets and obtain access to the motor, through the top, without removing the entire ventilator. For such a situation a structure such as shown in Figs. 10, 11 and 12 has been devised, in which the front wall 61 of cabinet 10 is hinged at its bottom edge by, hinges 62. Horizontal partition 22, curved ducts 63 and 63', and air directing chamber 64 are mounted on said hinged front wall 61 and may be tilted forwardly as shown in Fig. 12. In this position, filter baskets 27 and 28 may be removed upwardly from the openings in said partition and the filtering medium replaced. The

motOr and-fanunit may also be removed and oiled or repaired. A handle 65 permits adjustment of the vertical louvers.

In another construction shown in Figs. 13-16, hinged dampers 66 and 67 are inserted in upwardly curving converging discharge ducts 18, 18'. With damper 66 in the vertical position shown in Fig. 13,' it diverts the air and prevents it from discharging through the usual air directing upper chamber and out through the front wall of the cabinet 10. The air is diverted thereby into vertical flue 68 and is discharged into the room in a vertically upward stream through an opening (not shown) in the top 35 of the cabinet, which opening is aligned with 'ue 68. With damper 67 in the inclined position shown in Fig. 13, thel air passes through air directing chamber 69 and out through the front of the cabinet. The dampers are actuated through suitable linkage mechanisms 70, 71 and '72, 73 by means of shafts 74, 75, rotated by knobs '76 and 77 on the front of cabinet 10, as shown in Figs. 15 and 16. With this arrangement the air, especially when cold in Winter may be prevented from causing draughts Vin the room. If desired, one of the dampers may be open and the other closed as shown or they may be in any intermediate position so that any combination of air currents may be obtained to give the desired Ventilating and temperature effeet.

The compact constructions in the various gures, are capable of operating at high emciency, thereby noiselessly furnishing a large volume of silent, clean and directional air at low cost. This high efliciency results from a combination of features including the forwardly curved multiblade fans, streamlined ducts including streamlined louvers, the central partition in the curved duct leading upwardly and forward1y,'the perforated metal covered sound-absorber and a large filtering area. The device is noiseless in operation and quiets noises in the incoming air because of the vibration-absorbing construction and soundabsorbing construction. The air is cleaned of dust and dirt and may be freed practically of all pollen by the proper choice of filter sheet, thereby providing a means of relieving the suifering of hay-fever victims. The ltersmay be easily removed and replaced and likewise the unit construction permits of the ready removal of the motor and fan unit for servicing purposes.

I claim:

l. A ventilator comprising a cabinet having an intake opening and a discharge opening in the top portion thereof and having mounted at the bottom thereof air current creating means comprising two air propellers, each of said propellers having an axial air intake and peripheral air discharge, intake flues extending from said air intake opening and down the sides of said cabinet to said propeller intakes, discharge ues extending upwardly from said peripheral air discharges to said discharge opening, and sound absorbing material lining the fiues adjacent said air propellers, l

2. A ventilator comprising a cabinet having anintake opening in the top portion thereof and a discharge opening in the top portion of the front wall thereof and having mounted at the bottom thereof air current creating means comprising an air propeller mounted on each of both' ends of a.- motor shaft, each of said propellers having an axial air intake and peripheral air discharge, intake flues extending from said intake opening and down the sides of said cabinet to said intakes, air filters insaid intake fiues, and

discharge ilues extending upwardly from said peripheral air discharges converging into a duct extending forwardly to said discharge opening.

3. A ventilator comprising a cabinet having an intake opening in the top portion of the rear wall tion of the front wall thereof and having mounted at the bottom thereof air current creating means 4comprising an air propeller mounted on each of both ends of a motor shaft, each of said propellers having an axial air intake and peripheral air discharge, intake ilues extending from said intake opening and down the sides of said cabinet to said intakes, V-shaped air filters inthe vertical portion of each of both intake ues, said filters being removable through the tops of said ilues, and discharge flues extending` upwardly from said peripheral air discharges converging into a duct extending forwardly to said discharge opening.

4. A ventilator comprising a cabinet having an intake opening in the top portion of the rear wall thereof and a discharge opening in the top portion of the front wall thereof, air current creating means comprising a motor mounted on the bottom of said cabinet vibration absorbing supports for said motor, an air propeller mounted on each of both ends of the shaft of said motor, each of said air propellers having an axial air intake and peripheral air discharge, intake flues extending from said intake opening and down the sides of said cabinet to said intakes, the walls of said vertical fiues having a sound-absorbing lining, an air filter in each of said vertical flues, and discharge iiues extending upwardly from said thereof and a discharge opening in the top porperipheral air discharges and converging into a duct extending forwardly to said discharge opening, and sound absorbing walls in said discharge flues.

5. A ventilator comprising a cabinet having an air intake opening in the top portion of the rear wall thereof, a discharge opening in the top portion of the front wall thereof, a duct in the top portion thereof extending forwardly and connecting with said discharge opening, vertical iiues along the side walls thereof and connecting at the top of said cabinet with said air intake opening, said vertical ues having air filtering means mounted therein, a fan assembly mounted at the bottom of said cabinet, vibration-absorbing means between the base of said assembly and said cabinet bottom, said assembly comprising a motor having ashaft and an air propeller mounted on each of both ends of said shaft, vibration-absorbing supports for said motor mounted on said base, each of said air propel- 1ers having an axial air intake and a peripheral air discharge, said air intakes of said propellers connecting with said vertical flues, and discharge ilues extending upwardly from said peripheral air discharges and converging into a duct adapted to be connected to said forwardly extending duct, said discharge ues having sound-absorbing walls.

6. A ventilator comprising a cabinet having an air intake opening in the top portion of the rear wall thereof and a discharge opening in the top portion of the front wall thereof, air current creating means' comprising a motor in said cabinet, vibration-absorbing supports at the bottom of said cabinet for said motor, an air propeller mounted on each of both ends of the motor shaft, each of said propellers having ,an axial air intake and peripheral air discharge, intake ilues extending from said intake opening and down the sides of said cabinet to said intakes, the walls of the vertical nues having sound-absorbing linings, air filters in said vertical nues, discharge flues extending upwardly from said peripheral air discharges and converging into a duct extending forwardly to said discharge opening soundabsorbing walls in said discharge iiues, each pair of adjacent vertical intake and discharge fiues having a wall in common, means mounted in the iiue adjacent said discharge opening for changing both vertically and horizontally the direction of the air stream being discharged therefrom, and vibration-absorbing means between said cabinet and the base on which said propeller housings lare mounted.

7. A ventilator comprising a cabinet having an intake chamber in the top portion and a discharge opening in the front wall thereof, said cabinet having mounted at the bottom thereof air current creatinglmeans comprising two air propellers, each of said propellers having an axial air intake and peripheral air discharge, intake lues extending downwardly to said intakes along theA sides of said cabinet from said intake chamber, said intake chamber being formed by a horizontal partition across said cabinet near the top thereof, said horizontal partition having openings therein connecting said chamber with said vertical flues at each end thereof adjacent the sides of said cabinet, air filtering means adapted to be mounted removably in said openings, discharge ues extending upwardly from said peripheral air discharges and converging into a duct extending forwardly through said intake chamber to said discharge opening, and sound-absorbing material lining a portion of both said intake and discharge flues.

8. A ventilator comprising a cabinet having a discharge opening in the front wall thereof and a horizontal partition near the top thereof to divide said cabinet into a large lower chamber and shallow upper chamber, said upper chamber hav- ,ing an air intake opening in an outside wallv thereof, air current creating means mounted in said lower chamber having an axial air intake and peripheral air discharge, a discharge flue extending upwardly froin said peripheralair discharge through said lower chamber and through said horizontal partition and forwardly in said upper chamber to said cabinet discharge opening, said horizontal partition having an opening therein to allow the passage of air from said upper chamber to said lower chamber.

9. A ventilator comprising a cabinet'having a discharge opening in the front wall thereof and a horizontal partition near the top thereof to divide said cabinet into a large lower chamber and shallow vupper chamber having an air directing chamber therein, air current creating means in said lower chamber resting on the bottom wall thereof comprising two air propellers, each of said propellers having .an axial air intake and peripheral air discharge, converging vdischarge nues of sound-absorbing construction extending upwardly from said peripheral air discharges through said lower chamber and through said horizontal partition and forwardly in said upper chamber to said air directing chamber and said cabinet discharge opening, said horizontal partition together with saidair directing chamber in said upper chamber being formed as a unit separate from said air current creating means and converging flues in said lower chamber, said horizontal partition having openings therein at each end thereof adjacent the sides of said cabi- Leonesa net, a V-shaped air lter extending downwardly from each opening and supported therein, an outside wall of the part of said cabinet forming said upper chamber having an intake opening therein, and sound-absorbing linings on the interior walls of said cabinet adjacent said axial air intakes and below said horizontal partition.

10. A ventilator comprising a cabinet having the front wall thereof hinged at its bottom edge, said wall having a discharge opening therein, a horizontal partition integral with said hinged front wall dividing said cabinet into a large lower chamber and shallow upper chamber, said upper chamber having an air directing chamber therein, air current creating means mounted in said lower chamber comprising two air propel- 1ers, each of said propellers having an axial air intake and peripheral air discharge, vibrationabsorbing means in said lower chamber for supporting said air current creating means, converging discharge flues of sound-absorbing construction extending upwardly from said peripheral air discharges through said lower chamber, a continuation flue in said horizontal partition adjacent to and registering with the outlet of said converged discharge iiue, said continuation ue extendingforwardly in said upper chamber to said air directing chamber and said discharge opening in said hinged front wall, said horizontal partition having openings therein at each end thereof adjacent the sides of said cabinet, a V- shaped air filter extending downwardly from each of said openings, said upper chamber having an intake opening in an outside wall thereof, and sound-absorbing linings on the interior walls of said cabinet adjacent said axial air intakes and below said horizontal partition.

l1. In a ventilator comprising a cabinet having a top relatively movable to permit access to the interior of said cabinet, an intake opening and a discharge opening in the walls thereof, air current creating means mounted in said cabinet, and intake and discharge flues extending from said openings-in the walls of said cabinet to said air current creating means, shoulders in one of said flues, an open top lter basket extending across one of said nues in a position `accessible from the top of said cabinet and having extensions resting on said shoulders, Vwhereby said basket may be lifted therefrom, said basket comprising a frame and a filter sheet removably secured thereto to permit renewal thereof when said basket is removed.

12. In a ventilator comprising a cabinet having openings in the walls thereof and having air current creating means mounted therein, intake and discharge fines extending from said openings to said air current creating means, an open-end wedge-shaped air filter basket, removably supported in one of said flues and comprising a supporting structure consisting of two parallel V-shaped end walls spaced apart by means of cross members, two lateral converging walls comprising screens mounted in frames hinged at the wide end of said supporting structure and fastened together at their opposite ends,

and a continuous lter sheet facing the interior surfaces of said screens, said filter sheet being held at its edges between said screen frames and said supporting structure, said screens being adapted to be opened outwardly on their hinges to allow replacement of said filter sheet.

13. A ventilator comprising a cabinet having a discharge opening in the front wallvthereof and a horizontalv partition near the top thereof to divide said cabinet into a large lower chamber and shallow upper chamber, air current creating means mounted in said lower chamber comprising two air propellers, each of said air propellers having an axial air intake and peripheral air discharge, converging discharge flues extending upwardly from said peripheral air discharges through said lower chamber and through said horizontal partition and forwardly in said upper chamber to said cabinet discharge opening, saidhorizontal partition having openings therein at each end thereof adjacent the sides of said cabinet, an open-top wedge-shaped filter basket adapted to be mounted in each of said openings and extending downwardly therefrom each of said filter baskets comprising two V- shaped end walls and two lateral converging ltering walls comprising screens having an interior lining of a filter sheet,`each of said air lter baskets being suspended from the edges of each of said openings with its open-top upwards and removable upwardly therefrom, an outside wall of that part of said cabinet forming said upper chamber having an air intake opening therein.

14. A ventilator comprising a cabinet having a discharge opening in the front wall thereof, two units removably mounted in said cabinet, the first of said units being mounted on the bottom wall of said cabinet and comprising a motor shaft having air current creating means mounted thereon together with a discharge fiue extending upwardly from said air current creating means, and the second of said units comprising a horizontal partition extending across said cabinet near the top thereof, said partition having an opening therein and a discharge flue attached thereto and extending from said opening in said partition connecting with said upwardly extending fiue of said first unit to said cabinet discharge opening, said horizontal partition having an opening therein to allow air to pass from the chamber above said partition to the chamber beneath.

15. A ventilator comprising a cabinet having an air directing chamber therein and a discharge opening in the front wall thereof, two units removably mounted in said cabinet, the first of said units comprising vibration-'absorbing means mounted on the bottom of said cabinet, a motor mounted on said vibration-absorbing means, two air current creating means one mounted on each end of the motor shaft, together with converging discharge flues comprising sound absorbing walls extending upwardly from said air current creating means, and the second of said units comprising a horizontal partition extending across said cabinet near the top thereof, said partition having an opening therein with a discharge flue extending from said opening and connecting with said converged discharge flue of said first unit to said air-directing chamber and said cabinet discharge opening, said horizontal partition having openings therein at either end adjacent the end walls of said cabinet adapted to receive air filtering means.

16. A ventilator comprising a cabinet having a detachable front wall, said front wall having a discharge opening therein, two units removably mounted in said cabinet, the first of said units being mounted on the bottom wall of said cabinet and comprising a motor, two air current creating means, one mounted on each end of the motor shaft, together with converging discharge flues extending upwardly from said air current creating means, and thesecond of said units comprising said cabinet front wall, said front wall having attached thereto a horizontal partition extending across said cabinet near the top thereof said partition having an air directing chamber mounted thereon and an opening therein anda discharge flue extending from said opening and connecting with said converged discharge flue of said first unit to said air directing chamber and said discharge opening, said horizontal partition having openings therein, air filtering means adapted to be inserted in said openings.

17. A window ventilator comprising a cabinet having a discharge opening in said front wall thereof, two units mounted in said cabinet, the

first of said units being mounted on the bottom wall of said cabinet and comprising a motor, air current creating means mounted on the motor shaft, together with a discharge flue extending upwardly from said air current creating means, and the second of said units comprising a horizonal partition extending across said cabinet near the top thereof said partition having an opening therein and a discharge flue comprising a turret rotatable on a vertical axis extending from said opening in said partition connecting with said upwardly extending flue of said first unit to said chamber discharge opening, said horizontal partition having an opening therein to allow air to pass fromthe chamber above said partition to the chamber beneath.

18. A ventilator comprising a cabinet having a discharge opening in the front wall thereof, two units mounted in said cabinet, the first of said units being mounted on the bottom wall of said cabinet and comprising a motor, air current creating means mounted on the motor shaft, together with a discharge flue extending upwardly from said air current creating means, and the second of said units comprising a horizontal partition extending across said cabinet near the top thereof, said partition having an opening therein connecting with said discharge flue, a second discharge flue extending from said opening to said cabinet discharge opening, said horizontal partition having an additional opening therein to allow air to pass from the chamber above said partition axial air intake and peripheral air discharge, in-

take flues extending from said intake opening and down the sides of said cabinet to said intakes, air filtering units in said intake flues, discharge fiues extending upwardly from said peripheral air discharges converging into a duct extending forwardly to said cabinet discharge opening, an intake duct connecting said cabinet intake opening with a sourceof air outside of the room in which said ventilator is placed, and means in said intake duct comprising a recirculating valve to shut off the air coming from outside of said room and to recirculate the air in the room in which said ventilator is placed.

RALPH FORBUSH NORRIS. 

